Allergy Therapeutics plc

("Allergy Therapeutics", "ATL" or the "Group")

Allergy Therapeutics announces publication of three papers in the journal Allergy that strengthen the evidence base for Grass MATA MPL allergen immunotherapy

·      Key papers published in Allergy summarise the significant and clinically meaningful effect of Grass MATA MPL throughout the clinical trial programme

·      Independent patient survey results and clinical trial data were used to justify the Minimal Clinically Important Difference, further strengthening the positive outcome of the pivotal G306 Phase 3 trial of Grass MATA MPL

·      A meta-analysis of two phase III trials was published, showcasing comparable primary endpoint results and improved overall rhinoconjunctivitis quality-of-life in Grass MATA MPL compared to grass allergen immunotherapy products currently registered

·      Grass MATA MPL was shown to be effective and well-tolerated in the G306 study

31 July 2025 Allergy Therapeutics (AIM: AGY), the fully integrated commercial biotechnology company specialising in allergy immunotherapies, today announces the publication of three key publications in the journal Allergy supporting the efficacy, safety and quality-of-life effects of Grass MATA MPL, the Group's innovative subcutaneous immunotherapy (SCIT) candidate designed to address the cause of symptoms of allergic rhinoconjunctivitis due to grass pollen. Allergy is the official journal of EAACI with an impact factor of 12.6, the highest-impact journal in the field of allergy and clinical immunology.

Grass MATA MPL is an aluminium-free, pre-seasonal short-course immunotherapy designed to address the cause of symptoms of allergic rhinoconjunctivitis due to grass pollen, using six injections given prior to the grass allergy season. A Marketing Authorisation Application to the Paul Ehrlich Institut in Germany is currently under review, following the Group's submission in November 2024. Should this result in regulatory approval, commercial launch of the product is anticipated in FY2026.

Results from Allergy Therapeutics' G306 Phase III trial, which completed in November 2023, have been published by Zielen et al., showing that Grass MATA MPL met the primary endpoint, demonstrating a highly statistically significant reduction in the Combined Symptom & Medication Score (CSMS) of 20.3% (p=0.0005) compared to placebo over the peak pollen season.

Furthermore, a meta-analysis of the two Phase III trials in the Grass MATA MPL programme (G306 and G309) has also been published by Zielen et al., whereby 674 adult subjects with allergic rhinitis and/or rhino-conjunctivitis were included. The results of this meta-analysis showed a similar statistically significant improvement of 22.5% (p=0.00004) compared to placebo on the primary endpoint CSMS over the peak grass pollen season.

Most recently, Pfaar et al., have published a paper justifying that primary CSMS outcome improvements exceeding 16% are clinically relevant, confirming that Grass MATA MPL achieved levels of clinical relevance both in the G306 trial and the meta-analysis. In this publication, the minimal clinically important difference (MCID) for allergy immunotherapy trials was assessed using direct patient feedback and an anchor-based method using a data driven approach. The MCID is a level that represents the smallest change in CSMS that is perceived to be clinically important and meaningful or noticeable for a patient.

In a survey of 1071 grass allergic patients, the majority of participants (69%) considered a 1-point improvement (e.g., from "moderate" to "mild", or "severe" to "moderate") in their single most severe allergy symptom as clinically relevant. Furthermore, based on an anchor-based approach using the rhinitis quality-of-life questionnaire, an MCID of 16% and 0.22 points were justified as relative and absolute CSMS differences, respectively.

Taken together, these three papers complete the publication cycle for the adult-phase of the clinical programme evaluating Grass MATA MPL. The Group's G308 long-term paediatric study evaluating Grass MATA MPL in a paediatric population is ongoing, and the first cohort of grass allergic patients has completed their first grass pollen season.

Professor Stefan Zielen a.D., lead author from Goethe University Frankfurt and Institute of Respiratory Research, Medaimun GmbH Frankfurt am Main, Germany, said: "In Germany there is a significant unmet need for allergen immunotherapy products that directly address the cause of  allergic rhinoconjunctivitis due to grass pollen, and the excellent data seen throughout the Grass MATA MPL clinical trial programme support the use of a short-course subcutaneous immunotherapy to potentially fill this gap."

Professor Oliver Pfaar, lead author from the University Hospital, Philipps-Universität Marburg, Germany said: "As Chair of the EAACI task force, 'Minimal Clinically Important Difference (MCID) of clinical endpoints in AIT', I would judge this new evidence-based publication to be an impactful step in establishing a truly patient-centric research approach. Taken with the strong data across the Grass MATA MPL trials, these analyses are of utmost importance for patients suffering from the symptoms of grass allergy."

Manuel Llobet, Chief Executive Officer of Allergy Therapeutics, commented: "This marks the completion of the final stage of publication in our adult clinical evaluation programme for Grass MATA MPL. Building on the successful results achieved in the pivotal G306 study, these papers further validate our short course immunotherapy's potential to provide a vital treatment option for patients for whom seasonal grass allergy causes meaningful disruptions to daily life."

- ENDS -

Allergy Therapeutics

Manuel Llobet, Chief Executive Officer

Shaun Furlong, Chief Financial Officer

+44 (0)1903 845 820

Cavendish Capital Markets Limited (Nominated Adviser and Broker)

Geoff Nash /Giles Balleny/ Seamus Fricker

Nigel Birks - Life Science Specialist Sales

+44 (0)20 7220 0500

ICR Healthcare

Mary-Jane Elliott / David Daley / Davide Salvi

+44 (0)20 3709 5700

[email protected]

Notes for editors:

About Allergy Therapeutics

Allergy Therapeutics is an international commercial biotechnology company, headquartered in the UK, focussed on the treatment and diagnosis of allergic disorders, including aluminium free immunotherapies that have the potential to cure disease. The Group sells proprietary and third-party products from its subsidiaries in nine major European countries and via distribution agreements in an additional ten countries. For more information, please see www.allergytherapeutics.com.

About Grass MATA MPL

Grass MATA MPL is being developed as a pre-seasonal subcutaneous immunotherapy product for the treatment of allergic rhinitis and/or rhinoconjunctivitis.

Grass MATA MPL contains an extract of 13 grass pollens modified with glutaraldehyde to form allergoids that reduces the reactivity with immunoglobulin E (IgE) antibodies without a reduction in other important immunological properties, such as T-cell reactivity. The allergoid is adsorbed to microcrystalline tyrosine as a depot adjuvant system formulation. Monophosphoryl lipid-A (MPL), is included as an adjuvant to increase the immunogenic effect of the immunotherapy and to enhance the switch from an allergen specific helper T-cell Type 2 (Th2) to helper T-cell Type 1 (Th1) like immune response.